Henry w



(No Model.)

H. W. JOHNS.

0011mm FOR ELECTRIC WIRES.

No. 465,564. Patented Dec. 22, 1891.

ATTORNEY UNITED STATES PATENT OFFICE.

HENRY \V. JOHNS OF NEW YORK, N. Y.

CONDUIT FOR ELECTRIC WIRES.

SPECIFICATION forming part'of Letters Patent No. &65,564, dated December22, 1891.

Application filed April 1, 1891- Serial No. 387,316- (No model.)

To aZZ whom it may concern:

Be itknown that I, HENRY \V. JOHNS, a citizen of the United States, anda resident of New York city, in the county of New York and State of NewYork, have invented a certain new and useful Conduit for Electric Wires,of which the following is a specification.

My invention relates to an improvement in conduits for electric wiresspecially intended for interior work, although adapted also under manyconditions to outside work.

Figure 1 illustrates an elevation of a piece of my improved conduit.Fig. 2 illustrates an end view thereof.

I-Ieretofore various means have been em- I ployed for protection ofelectric wires, especially upon the inside of buildings. Such conduitsor protections should have three distinctive qualities: First, theyshould be sufficiently strong to withstand blows or shocks to which theyare liable; second, they should be fireproof, and, third, they should bewater-proof. Various attempts have been made to give such conduits thesequalities, but not, asI believe, with very great success. By myinvention I secure, as I think, a completely satisfactory article forthe use stated.

In constructing my improved conduit I take a piece or strip of strongasbestus paper and wind it about a mandrel, or otherwise, so as to forma tube. This may be done by wind ing a series of strips superposed uponeach other, all wound the same way or in difierent ways, as desirable;or it maybe made of a single thickness of material wound so that theedges meet one another, edge to edge, or overlapping, as preferred. Theexterior and interior may be coated with cementing material to addstrength and smoothness to theinside and outside, so that the finishedtube may be easily placed in position and so that the wires may bequickly and easily inserted therein; or the tube may be formed directlyfrom waterproofed asbestus pulp byany suitable me chanical means, andcementing matter may be added to the asbestus pulp to add to the densityand strength of the product, and this pro duct may have an outer layerof asbestus paper or cloth added for strengthening and other purposes.In the figures of the drawings 1 show it as made of a series ofoverlapping strips wound in opposite directions, so as to give increasedstrength. A A are the strips. B shows the meeting edges of the outerlayer and O the meeting edges of one of the under layers. There maybe asmany layers superposed upon one another as desired. In order that thetube may be a stiff strong structure, I cement the sheets together withany suitable cementing material. For this purpose I prefer a fire-proofmaterial such as silicate of soda, and in order to give the water-proofquality to the product it may be treated or coated with any suitablewaterproofing material, such as oil, shellac, india-rubber solution, orcement and thelike. The shellac and the india-rubber will themselvesserve both to waterproof and to adhere or cement the materialtogetl1er,if preferred ,or the asbestos paper or sheet may be renderedwater-proof during the process of manufacture, which will render theproduct both fire-proof and waterproof.

Also, before the cementing material is dry I may add powdered mineralmatter, such as oxide of zinc, powdered asbestus, or the like; or I maymake a thick fire-proof coating or paste embodying suitable mineralmatter and coat the inner or outer side, or both, to form a strengthenedplaster-like tube, in which case I can use Manila or other paper insteadof asbestus. As above stated, I prefer a fireproof material such assilicate of soda or other cementing material having substantially thesame characteristics, becausethen in the event of a hot wire touching itthe cementing material will not be either burned or fused or becomesoftened, as would be the case with rubber or asphaltum or glue or' anysimilar cementing material, some of them being inflammable and some ofthem, while not strictlyinflan1mable,are readilysoftened byheat, so thatthey lose their holding or cementing quality. For outside use anadditional coating of asphalt or other water-proof material may beapplied to give greater strength and resisting power to withstandabrasion and the action of the elements. I may also attach or melt ormold upon the tube a sheet or film of lead or other metal. The asbestospaper, being the proof, will not be injured by molten metal.

I claim 1. A conduit for electric wires, composed of strips of compactedasbestus fiber wound in opposite directions, and waterproofing ma terialand cementing material, substantially of compacted asbestus fiber woundin oppoas set forth. X site directions, fire-proof and infusible ce- 2.A conduit for electric wires, made, cssenmenting material,andwaterproofing material, I 5 tially, of compacted asbestus fiber,fire-proof substantially as set forth. 1 and infusible cementingmaterial, and water- Signed at New York, in the county of New proofingmaterial, substantially as set forth. York and State of New York, this18th day of 3. Aconduitfor electric Wires, madeof com- March, A. D.1891. pacted asbestns fiber, fire-proof and infusible cement,waterproofing material, and an ex- 7 1o terior protecting andstrengthening layer or Witnesses:

covering, substantially as set forth. PHILLIPS ABBOTT, 4. Aconduitforelectricwires,made of strips E. W. GIFFORD.

HENRY W. JOHNS.

